Using his newfound powers, Gog killed Superman. Unsatisfied by his victory, Gog went back in time one day, found Superman, and killed him again, repeating the process over and over, each time varying the means of Superman's death and absorbing portions of the slain Supermen's power. When he arrived on the day that Superman and Wonder Woman's child was born, the entire Justice League tried to stop him, but they failed, and Gog took the child, deciding to go directly to the past where he intended to trigger the Kansas cataclysm almost twenty years early, burning Superman's insignia into the countryside.
Gog's actions exposed the existence of Hypertime, a fictional construct similar to the Multiverse in pre-Crisis stories. Gog unknowingly passed into an alternate timeline each day he traveled back in time, effectively killing a different Superman at every turn. As a result, the Phantom Stranger was forced to recruit time traveller Rip Hunter of the Linear Men, the only other person aware of Hypertime, in an attempt to preserve the secret, the other members of the Quintessence refusing to act to stop Gog for their own personal reasons.
Rip Hunter, refusing to believe the other Linear Men's claims that travelling back in time would destroy the Kingdom Come reality, recruited Batman, Superman, Wonder Woman, Kid Flash III (daughter of Wally West), Offspring (son of Plastic Man), Nightstar (daughter of Nightwing and Starfire), and Ibn al Xu'ffasch (son of Batman and Talia al Ghul) from the Kingdom Come reality, along with the Superman, Batman and Wonder Woman from the present to fight Gog, luring him into Booster Gold's "Planet Krypton" a superhero-themed restaurant that had been stocked with artifacts from various realities before Hunter moved the restaurant outside of time to limit civilian casualities. With the available arsenal, the heroes managed to wound Gog, with Batman using a Phantom Zone projector to partially send Gog into the Zone, severally scarring him while the heroes armed themselves. Gog fights back, knocking the heroes down as he himself collapsed in a weakened state. Unable to move from the force of the attack, the present Superman is convinced to fight back by the future Wonder Woman, who told him of the destruction of Kansas and how it happened as a result of him abandoning his fight for truth and justice following the death of Lois Lane. Refusing to allow history to repeat itself, Superman charged at Gog, who sends both of them and everyone else in the restaurant into Hypertime, thus allowing Hunter to preserve the Kingdom Come reality. Gog is then returned to the future by Rip Hunter and the future versions of Superman, Batman, and Wonder Woman, who demand that the Quintessence restore him to the person he was.
Eventually, he succeeds in his efforts at creating a time machine, but his first prototype is unable to travel far enough back. He refines the time machine for over two-hundred years, making it more and more powerful and using the technology to give himself super-powers. He then gives his research and advanced technology to younger versions of himself, which gives him more power due to rewriting history over and over. Eventually, his desire grows from saving his parents to punishing Superman for their deaths.
The present day Gog attacks Superman when Doomsday returns to Earth with newfound sentience and begins discovering emotions during his rampage. Doomsday arrives to see Superman on the verge of death after being beaten by an army of Gogs. Doomsday leaps to Superman’s defense just as Gog is about to kill him. Doomsday’s attempt to save Superman fails as Gog successfully kills him.
Over the next two-hundred years, Doomsday leads an army in Superman’s name against Gog. This future is erased when it is revealed that Gog didn’t actually kill Superman but has instead been keeping him prisoner and surrounded by Kryptonite.
Gog offers Superman the chance to go back in time and kill him. Superman eventually shows Gog the error of his ways when Doomsday bursts in and rescues Superman. Gog then offers Doomsday the chance to go back and erase this future at the cost of his own sentience which he agrees to. In the present, the present day Gog teleports away an unconscious Doomsday for unknown reasons.
This version of Gog (The book is actually not that clear on his identity in relation to the previous Gog, and it is possible they are meant to be one and the same, with his actions in the storyline mentioned above a consequence of his delusional state) is a priest named William Matthews who received his powers from an underground citadel in Africa and took the name Gog, which was the name of the last surviving god of the Third World. He also claims that the Superman of Earth-22 let Kansas die. When the JSA lead him back to the citadel, his body is absorbed by a stone face on a wall. The stone face rises, becoming a massive stone man adorned in gold who claims to be the one, true, Gog.
This fourth Gog, chronologically the first one, is an exile of the Third World who was unwilling to take sides in the final battle of the Old Gods and was cast off as a result. He then plunged into the Bleed and traveled through various alternate universes until he landed on New Earth. Inert, his consciousness lingered in the stone and lava. A local tribe built a staff out of his remnants, enabling a user to channel Gog's powers. The staff was later found by William Matthews, who claimed the name Gog.
Upon being revived, Gog claims that Matthews wasn't his servant and that Matthews had been driven mad from visions of the Multiverse, including having visions of events on Earth-22.
This version of Gog displays a cheerful, child-like, peaceful personality. He claims he is "happy to be alive" and compelled to "make things good again". He saves an African village near his citadel from the effects of toxic contamination from lava that contained his essence and heals Damage's disfigured face in response to his skepticism. Gog then sends Sandman to a blissful, dream-filled sleep for twenty-four hours, cures Starman of his schizophrenia, gives Doctor Mid-Nite his sight back, and sends Power Girl "home". Gog then hears the noises of a war going on near by and vows to stop it. Finding a small village under attack by a rogue militia, Gog transforms the soldiers into trees. During the conflict, Lance, one of the JSA's new recruits, is hit by a rocket launcher blast and killed. Gog brings Lance back to life, replacing his ruined arm with gold armor, and renames him "Magog".